VA Medical Center Introduces New Non-Invasive Diagnostic Tool
Identifying Patients at Risk for Sudden Cardiac Events

The Houston VA Medical Center has announced that it is offering the Alternans Test, the first non-invasive diagnostic test approved by the FDA to identify patients at risk for electrical malfunctions of the heart that lead to sudden cardiac arrest (SCA). Sudden cardiac arrest claims more than 300,000 lives a year in the United States and is the nation's leading cause of death. With the Alternans Test, Dr. Jaggarao Nattama, electrophysiologist at the Houston VA Medical Center, hopes to identify patients at risk for cardiac events earlier than was possible before, and direct them to appropriate preventative treatment. Dr. Nattama has administered the test to several patients already.

The Alternans Test was approved by the United States Food & Drug Administration (FDA) in April 1999 as the first non-invasive cardiac diagnostic test to predict risk for ventricular arrhythmias, the electrical irregularities in the heart that lead to sudden cardiac arrest. The Alternans Test works like a "super stress test" and measures extremely subtle beat-to-beat fluctuations in a person's heartbeat called T-wave alternans. These tiny heartbeat variations - measured at one millionth of a volt - are detected during a typical treadmill or bicycle exercise stress test by specially designed, high-resolution electrodes placed on a patient's chest.

Most patients considered at risk for heart disease have an exercise stress test; approximately 9 million stress tests are conducted each year in the United States. The stress test can identify patients at risk for ischemic heart disease or "clogged arteries" but is not able to detect patients with arrhythmic heart disease or "electrical problems" that can lead to SCA. Because it can identify these electrical irregularities, the Alternans Test fills a major gap in current cardiac disease diagnosis. Patients identified as being at risk for SCA can be treated with preventative measures, including receiving an implantable cardioverter defibrillator (ICD).

Dr. Nattama says, "The Alternans Test is an important new diagnostic tool and we're excited that the Houston VA Medical Center can now offer it to our patients. More then 300,000 Americans die each year from sudden cardiac arrest. The Alternans Test will help us to better identify those at risk for SCA early enough so that we may prescribe appropriate preventative measures."

About the Alternans Test
The Alternans "super stress test" is a fully featured diagnostic system that includes a cart-mounted computer with proprietary software, integral ECG system, display, keyboard and output devices that can be configured for both hospital and office settings. The system is designed to support a broad range of standard and physician-customized protocols for the conduct of cardiac stress tests and is compatible with both standard electrodes and hi-resolution electrodes for the detection of T-wave alternans. The system is capable of controlling treadmill and bicycle ergometers, devices used to exercise the patient during the test.

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